How can i find out if someone made a fake account on facebook. read description.?

[Sepehr]

basically someone has made a account on facebook with a ridiculous name (hendontboyyear11) has been posting ridiculous things on the facebook page about people in my school and i think i know who it is. this person that i think it is also has a facebook account. i want to find out if both accounts came from the same ip address. how can i do this. or is there any other way for me to find out if these two accounts are made by the same person
ethan i already know its a fake account i just wanna find out if this fake person was made by one of my friends. which is why i wanna track the ip address of both profiles to see if they match

[Ethan]

https://www.facebook.com/notes/k-care-sh...0043898294
Here you go. I hope this helps